#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>

int main()
{
    printf("process is running, only me, pid: %d\n", getpid());
    sleep(3);
    pid_t id = fork();
    if (id == -1) return 1;
    if (id == 0)
    {
        //child
        while (1)
        {
        printf("id: %d, I am chile process, pid: %d, ppid: %d\n", id, getpid(), getppid());
        sleep(1);
        }
    }
    else 
    {
        //parent
        while (1)
        {
        printf("id: %d, I am parent process, pid: %d, ppid: %d\n", id, getpid(), getppid());
        sleep(2);
        }
    }

    //pid_t id = getpid();
    //pid_t pid = getppid();
    //while (1)
    //{
    //    printf("I am a process, pid: %d, ppid: %d\n", id, pid);
    //    sleep(1);
    //}

    return 0;
}
